logrewrite.scala

package fix

import scalafix.v1._
import scala.meta._

class RewriteToStructured extends SemanticRule("RewriteToStructured") {

  override def fix(implicit doc: SemanticDocument): Patch = {
    doc.tree.collect {
      case logger@Term.Apply(Term.Select(loggerName, methodName), List(Term.Interpolate(Term.Name("s"), parts, args))) if matchesType(loggerName) =>
        println(logger.structureLabeled)
        Patch.replaceTree(logger, rewrite(loggerName, methodName, parts, args))
    }.asPatch
  }

  private def matchesType(name: Term)(implicit doc: SemanticDocument): Boolean = {
    name match {
      case Term.Name(n) if n == "logger" =>
        true
      case _ =>
        false
    }
  }

  private def rewrite(loggerTerm: Term, methodTerm: Term, parts: List[Lit], args: List[Term]): String = {
    // if the argument is a literal, like s"${3}" then don't switch it.
    // if the argument is a method or function, then don't switch it.
    // if the method is a field, then it's safe?
    val values = args.map { arg =>
      //println("arg = " + arg.structureLabeled)
      s"""fb.value("$arg", $arg)"""
    }

    val literal = parts.map { p =>
      p.value.toString
    }.mkString("{}")

    val statement = if (values.size > 1) {
      s"""fb.list(${values.mkString(", ")})"""
    } else {
      values.mkString("")
    }

    s"""$loggerTerm.$methodTerm("$literal", fb => $statement)"""
  }
}